pgsql: Support for KOI8U encoding

Log Message:
-----------
Support for KOI8U encoding

Modified Files:
--------------
    pgsql/doc/src/sgml:
        charset.sgml (r2.90 -> r2.91)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/charset.sgml?r1=2.90&r2=2.91)
    pgsql/src/backend/utils/mb:
        encnames.c (r1.37 -> r1.38)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/encnames.c?r1=1.37&r2=1.38)
        wchar.c (r1.70 -> r1.71)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/wchar.c?r1=1.70&r2=1.71)
    pgsql/src/backend/utils/mb/Unicode:
        UCS_to_most.pl (r1.6 -> r1.7)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/Unicode/UCS_to_most.pl?r1=1.6&r2=1.7)
    pgsql/src/backend/utils/mb/conversion_procs:
        Makefile (r1.20 -> r1.21)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/conversion_procs/Makefile?r1=1.20&r2=1.21)
    pgsql/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic:
        utf8_and_cyrillic.c (r1.23 -> r1.24)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/conversion_procs/utf8_and_cyrillic/utf8_and_cyrillic.c?r1=1.23&r2=1.24)
    pgsql/src/include/mb:
        pg_wchar.h (r1.83 -> r1.84)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/mb/pg_wchar.h?r1=1.83&r2=1.84)
    pgsql/src/port:
        chklocale.c (r1.10 -> r1.11)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/port/chklocale.c?r1=1.10&r2=1.11)

Added Files:
-----------
    pgsql/src/backend/utils/mb/Unicode:
        koi8u_to_utf8.map (r1.1)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/Unicode/koi8u_to_utf8.map?rev=1.1&content-type=text/x-cvsweb-markup)
        utf8_to_koi8u.map (r1.1)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mb/Unicode/utf8_to_koi8u.map?rev=1.1&content-type=text/x-cvsweb-markup)